Sand blasting nozzle



Dec. 25, 1962 s. D. SHELTON-V SAND BLASTING NOZZLE 2 Sheets-Sheet 1 Filed Aug. 8, 1960 INVENTOR. GEORGE D. SHELTa/V-V Dec. 25, 1962 e. D. SHELTON-V SAND BLAS'IIING NOZZLE 2 Sheets-Sheet 2 Filed Aug. 8, 1960 V W #N MN NM M Y @N m m E \N m L W W M a .Q \w 5 r m N N 0. D 4 \N E 6% 6 Q Q w m w MN E G BE NM & mw w\ & m QN N D\ N\ I -Q\\ w @HRN. Nw 475 V L. A

L Q .3 \W QW N\ FQN\ 3,069,812 Patented Dec. 25, 1962 lice 3,969,812 SAND BLASTING NGZZLE George D. Shelton V, 4455 4th St, Riverside, Calif. Filed Aug. 8, 1966, Ser. No. 48,153 1 Claim. (Cl. 51-41) This invention relates generally to sand blasting equipment and more particularly to a new and improved sand blasting nozzle.

Sand blasting, widely used for surface preparation and for surface abrasion, utilizes sand, steel grit, or other abrasive particles impinged at high speed against the surface being treated. Customarily, the supply of abrasive particles is fed through a hose to a hardened steel nozzle which has a constriction in its bore. The constriction, causes the abrasive particles, under high pressure, to be expelled with force and accelerated so as to impinge upon the surface being abraded.

Because of the constriction in the nozzle, and the abrasive force of the particles, these nozzles have very short useful lives and must be replaced frequently at relatively high cost.

I have devised an important new and improved sand blasting nozzle utilizing air injection to accelerate the particles. With this nozzle I am able to eliminate the usual constriction in the nozzle and, yet, provide better surface abrasion. The wear on the interior of this new type nozzle is greatly reduced.

Thus, it is an important object of this invention to provide a sand blasting nozzle utilizing air injection to accelerate the abrasive particles.

It is a further object of this invention to provide an improved sand blasting nozzle in which the abrasion on the interior of the nozzle is reduced.

It is a further object of this invention to provide an improved sand blasting nozzle in which the abrasive particles are provided with increased velocity and increased flow.

The foregoing and other objects and advantages of this invention will be clear to those skilled in the art upon reading the following description in conjunction with the accompanying drawings in which:

FIGURE 1 is a side elevation of a preferred embodiment of a sand blasting nozzle of my invention;

FIGURE 2 is an enlarged front view of the same embodiment with the handle partly broken away;

FIGURE 3 is a section on 3-3 of FIGURE 2;

FIGURE 4 is a section on 4-4. of FIGURE 3, taken as though FIGURE 3 was not itself in section;

FIGURE 5 is a section on 5-5 of FIGURE 4 on a portion of the nozzle taken as though FIGURE 4, itself, was not in section;

FIGURE 6 is a section on 6--@ of FIGURE 3 on a portion taken as though FIGURE 3 was not in section; FIGURE 7 is a perspective of part number 17; and

FIGURE 8 is a partial section of the upper front as seen in FIGURE 3 but in alternative form with air holes l8, l9 and 20 of different sizes as explained in the description.

The nozzle consists of a cylinder it having a bore (unnumbered) throughout its length. Said bore is of a diameter equal to the internal diameter of the particle supply hose 4% being used in the operation. In various circumstances this might be one half inch diameter, one inch diameter, or any other size as will be clear to those skilled in the art.

The cylinder 11 is provided with threads 11a at one end to accommodate the threads 41a on the hose coupling 41.

Cylinder I1 is provided with a shoulder (unnumbered) near its threaded end suitable to accommodate collar 12.

2 Cylinder 11 has three sets of forwardly inclined holes, 13, 19, and 20, at spaced distances about its circumference, and extending through its walls. Cylinder 1.1 is, likewise, provided with two sets of diametrically opposed holes 21 at its discharge end.

Collar 12 is provided with threads 12:: to engage threads of sleeve 10. Gasket material 22, 22a and 23 forms tight seals so that an air chamber Ida is formed about the outer circumference of cylinder 11, as shown.

Sleeve it) has a handle so formed integrally, welded, or otherwise making a solid and air tight connection. Handle 39 is bored 34 through its length and into communication with chamber Illa.

A series of holes 18 (four are used here, but any other convenient number might be used) are provided through the wall of cylinder 11, and at uniform distances about its circumference inclined forwardly, and communicating between the bore of cylinder 11 and air chamber 16m A similar series of holes 19, and another similar series of holes 24 are provided at spaced intervals as indicated.

A valve 33 of any customary air valve construction openated by finger button 32 controls the flow of air into air chamber Ida and thus the flow of air through holes 18, 1% and 20.

The two additional groups of holes 21 provided on opposite sides of the discharge end of cylinder 11 intercommunicate with air chamber 10a through the chamfered portions 24- of control ring 17.

Control ring 17 is held in position by screws 14 and through sleeve It Front ring 17 may be rotated so that the chamfered portion 24 allows air to pass to holes 21, or it may be rotated so as to shut off the air from all or any portion of the holes 21, always so moving that if any holes are open a uniform number of diametrically opposed holes will be open on each side.

Set screws 14 are loosened or fastened through holes (unnumbered) in knurled ring 13. When set screws 14 are loosened ring 17 is shifted relative to cylinder 11 by turning the knurled ring 13. Set screws Ila slide in slots 14a in sleeve ltl. In position 24a as shown in FIGURE 4 air will pass through all of holes 21 and in position 24b as shown in FIGURE 4 no air will pass through holes 21. When the rings 13 and 17 are in the appropriate position for the operation desired, set screws 14 are tightened. Thus it may be set so none of the holes 21 are open, or so that 1 or more of the holes on each side are opened.

The purpose of holes 21 is to allow air to pass on opposed sides of the discharge opening so that the spray of abrasive particles may be fanned if desired. When no holes 21 are open, there will be a spot of abrasive particles being generally circular in pattern. As more of the holes 21 are opened, this spot becomes oblong. Thus, the width of the area being abraded may be controlled.

The acceleration air through holes 13, 19 and 2% speeds the particles through the nozzle, at the same time providing a laminar flow of air such that there is little or no contact of particles with the interior surface of the nozzle.

To achieve different speeds and discharge of abrasive particles, all of the holes l8, l9 and 2d may be the same size, or the rearward holes 24 may be larger, forward holes 1% smaller, and intermediate holes 19 of intermediate size as shown in FIGURE 8; or, this may be reversed so that holes 18 are largest, 19 intermediate and 2d smallest as shown in FIGURE 3.

In operation, a sand blast hose coupling is screwed onto the thread 11a of the nozzle body. A source of air under pressure is supplied through hose 36 so that the chamber 19a between the sleeve 10 and the wall of the nozzle 11 becomes an air chamber under pressure. Air then flows through the small holes 18, 19 and 20.

The successive series of holes within the tube discharge the air at high velocity into the nozzle. Since the holes 18, 19 and 20 are inclined towards the discharge end, a laminar flow of air is created within the tube. The air in the center of the tube flows more rapidly than the air near the walls of the tube. This principle will be understood by those who have studied air current, particularly jets meeting under pressure in a confined area and flowing in a lateral direction.

When air flows through the holes 21 at two diametrically opposed sides or" the discharge and of the nozzle a fan-like effect is created and causes the particles emanating from the nozzle to be spread in a fan-like pattern in order to broaden the area of coverage upon the surface being sand blasted. As previously described, the control ring 17 may be shifted to open or close as many of holes 21 as desired. Depending upon the surface being Worked and the results desired, this pattern may be altered.

In operation, the source of sand is delivered in the customary manner through a suitable hose 40 connected to the sand blast nozzle. The air source is supplied to the chamber around the sand blast nozzle and feeds through the holes l8, l9 and 2t} into the nozzle and outward and emanating from the end of the nozzle.

As the source of sand or other abrasive material enters the nozzle, it is picked up in the air flow and because of the laminar flow is confined to the center of the nozzle and thus does not create a bad abrasion against the sides of the nozzle. By the injection of the air stream, the particles are greatly accelerated in speed in a manner comparable to, but superior to, that created by the mechanical constriction in a normal sand blast nozzle. As the abrasive material emanates from the discharge end, it is fanned by the air from the holes in the discharge end as desirable for the particular operation.

In the particular device shown, I have used three series of four holes about the circumference of the nozzle Within the air chamber. It will be clear to those skilled in the art that the result desired might be obtained by a greater or lesser number series of a lesser or greater number of holes spaced about the circumference and the holes could be so distanced that they were not exactly in alignment from the end or either end of the nozzle. All of such modifications as might be made will be clear and apparent to those skilled in the art.

I claim:

A sand blasting nozzle comprising: A first tube having an intake opening at one end and .a discharge opening at the other end, a plurality of holes through its walls inclined to outside to inside in the direction of the discharge opening and two sets of diametrically opposed holes at the discharge end extending through the walls of said tube and inclined from the outside to the inside of said tube directionally outward from the discharge end; a second tube having a hole through its Wall fastened about said first tube at a distance therefrom so as to form a chamber about said first tube; an air supply hose con nected to and communicating with said hole in the wall of said second tube; a rotatable ring located within said chamber at the discharge end, having a portion of its circumference cut away so that on rotation it may open said diametrically opposed holes to communication with said chamber, or cut them oil from such communication; and a supply for abrasive particles attached to the intake opening of said first tube.

References Cited in the file of this patent UNITED STATES PATENTS 2,376,616 Oechsle May 22, 1945 2,571,874 Hale Oct. 16, 1951 2,821,346 Fisher Jan. 28, 1958 2,990,653 Browning July 4, 196 1 FOREIGN PATENTS 560,669 France July 16, 1923 

